Clock and inter-combination line frequency separation in $^{171}$Yb

TL;DR

This paper reports precise optical frequency measurements of specific transitions in $^{171}$Yb, determining the frequency separation between two key energy levels with ppb accuracy, aiding future experiments without highly accurate standards.

Contribution

The study provides the first precise measurement of the frequency separation between the $^{3}P_{0}$ and $^{3}P_{1}$ levels in $^{171}$Yb, improving the accuracy for related experiments.

Findings

Frequency separation determined with ppb uncertainty.

Enhanced understanding of $^{171}$Yb energy levels.

Facilitates experiments without high-precision standards.

Abstract

We have carried out concurrent optical frequency measurements of the $(6s^{2})\,^{1}S_{0} -(6s6p)\,^{3}P_{1}$ ($F=\frac{3}{2}$) and $(6s^{2})\,^{1}S_{0} -(6s6p)\,^{3}P_{0}$ transitions in $^{171}$Yb, and in so doing have determined the frequency separation between the $^{3}P_{0}$ ($F=\frac{1}{2}$) and $^{3}P_{1}$ ($F=\frac{3}{2}$) levels with an uncertainty in the ppb range. The knowledge of this frequency interval will aid experiments relying on the $^{1}S_{0}-\,^{3}P_{0}$ line in $^{171}$Yb and $^{173}$Yb without access to highly accurate frequency standards.